Magazine fuse plug



P. MQ'CARMlcH-AEL. MAGAZINE FUSE' PLUG. APPLICATION FILED JUNE I2, 1920.

Patented Aug. 15, 1922.

PATENT OFFICE.

i PETER M. CARMICH'AEL, OF YORK, N. Y.

iinlualazrivE rusnrnue.

Applica/cien med June i2,

' To all eohoma't may concern:

Be it known that I, Pn'rnn M. Campionaria, a'citizen of the United States,x residing at New .York city, in the county o1' New York,

State of New ,Yorld have invented certain `new and useful Improvements in Magazine Fuse Plugs; and 1 do hereby declare the following tob'e a full, clear, andexact description of the invention, such as will en-k able others skilled in the art to which it appertains to ymain-rand use 'the same.

This invention relates to improvements' in electric fuses* and particularly to magazine fuses. j c

One 'object of the invention'is to provide a novel and simple device of this character which can be 4screwed into the socket `oit a junction boX, iny the nianner 'of the ordinary fuse plug, and when one of the Jfuses burns out it is 'only necessary yto rotate a certain part oi" the plug` to bring into play a new fuse, thus obviatingthe usual procedure of y the line 3 8 of Figure 1;

removing the fuse and "placing a new one in the socket.

Other objects reside in the peculiar construction and arrangement of the various desired results are ob-` parts whereby the tained.

In the drawingz."` Figurel is an elevationof a fuse made in accordance with my invention;

Figure 2 is a bottom plan view of the rotlyplu's ,L y

Figure Bis an enlarged vertical section on Figure ellis atop 'plan view 'of the device with therotatable plug removed. y

Referring new to the drawings, n the` present plug comprisesa porcelain body 10, having a circuinscribing*flange11 atone end and the upper portion of which 'flange `is slightly enlarged vas shown lat 11a f and knurled as illustrated, to facilitate screwing and unscrewing'of the plug. The opposite end portion oi the plug body is reduced in diameter as shown at 11. Upon the body portion 10 is fitted a metallic sleeve 12 in which are pressed the usual threads 13 to engage the threads of the socket into which the plug is to be screwed, this sleeve 12 being hanged inwardly at its lower end as shown at 12 against the corresponding portion of the body 10. i

Through the upper end of the body 10 is formed a cavity 14, the upper portion of which. is countersunken with a resultant 192e. seria; No. 388,502. y

shoulder lfand within'the countersink'a'nd upon this shoulderis disposed a plug disk 116,"als`o` of porcelain or "other suitable'insu lating material. y

About the body portion l()l and directly adjacent 'the flange 11, there is formed acircum'seribing groovef`17 and the sleeve 12 specification of Le-rreiysraient. Patented- A'g 15, 1922. i

above re-'erred to, projects upwardly so as to enclose thelower portion of this channeLFas clearly illustrated in Figure 3. y

lFormed through the flange 11'of the porcelain is an annular series ci cylindrical pas'- sages 18, 'which annular series is coaxial with thev body 10and these passages have their lower ends directly above the upper edge of the sleeve 12. The passages lead through the shoulder 15 at the bottomo the countersink of the cavity 14C. Leading inwardly and radially from each cylindrical passage 18 isa channel 18 formed in the shoulderl, and each of these channels 18 communicates with a groove 19 formed longitudinally of the'wall ofthe cavity 14. A plurality of ifiuse wires 19 are provided, each of inverted U-shape. Each fuse wire 19 is disposed with one leg in a groove 19', and with its other leg ina passage 18, while its communicating or bight portion is disposed in the corresponding channel 18. The 'leg in the passage 18 is longer than the other leg and continues downwardly into the channel 17 where it is soldered or otherwise electrically connected with the sleeve 12. @n the under side of the disk 16, and extending from the center to the edge thereof' is a brass spring bar 21." The inner end of this bar has an eye 'loop' 22 in which is "connected the upper end of a helical spring 23, said spring eX- tending down through Ythe cavity 14 and through an o'pening24 in the lower'portion of the plug where it is connected to a metal contact .member 25J This member. is disposed centrallyon Vthe inner end of the plug and is'adapted to contact with the spring in the center of the ordinarysocket. The outer tace of thedisk is provided'with a' knob 26 by means' of which the disk may be rotated.

The disk 16 is provided with an index 30 on its upper face, while upon the flange 11 and over each of the fuse wires is marked a number as indicated. The index 30 is di* rectly over the contacting spring 21 so that the spring will make contact with that fuse wire whose number is opposite to the index.

In operative position, the outer end of the member`21 is'in metallic contact with the portion of one of the :fuse wires 19 that lies in a channel 18 so that current will pass from the member 25, through the spring 23, the member 21, one of the fuse Wires 19 and the metallic sleeve. Should the fuse wire burn out, it is only necessary to rotate the disk 16 so as to bring the outer end of the member 21 in contact with the outer end oi another fuse Wire, the contact 25 rotating with the spring and the disk 16. In order to prevent the flash ont' a burning fuse wire from affecting adjacent wires, the face or shoulder 15 is provided, intermediately of the grooves or slots 18', with 'the radially extending shoulders or ribs 27, said ribs 27 providing dividing walls be tween the several fuses. The cap disk 16 is provided with correspondingly formed radial grooves or recesses 28 which lit over the ribs 27 when the cap disk 16 is lowered into position with the contact strip 21 in engagement with one or' the fuses. Thus when the active fuse blows out, the danger of its affecting any olf' the adjacent fuses is obviated. The intertting elements 27 and 28 also provide a means for accurately positioning the Contact strip 21 over any one of the iuse wires. The spring 23 exerts a Constant pull upon the cap disk 16, to seat the latter and also to hold the contact strip in engagement with the fuse wire. Thereiore, if it is necessary to rotate the disk to position the contact strip over a new fuse wire, the cap is lifted against the action of the spring 23 to disengage the elements 27 and 28, aiter which the cap disk may be rotated to the desired new position and reseated in contact with anew fuse wire.

To protect the spring 3 against the heat lfrom the melting fuses, a cylindrical casing 2l of any suitable insulating refractory material may be disposed over it.

ifVhat is claimed is:

1. An electric iuse plug comprising a body having socket engaging contacts and channels leading to one of them, fuse wires disposed in the channels and connected with the contact to which the channels lead, the body having also radial ribs alternating with the 'fuse wires, a rotatable cap for the body having radial grooves disposed to receive the ribs respectively and separate the fuse wires, a contact carried by the cap and rotatable therewith into engagement with the fuse wires successively, and a resilient conducting element connected between the last named contact and with the socket engaging contact to which the fuse wires are not connected and under the iniiuence of which resilient member the cap is held yieldably with the ribs in the grooves.

2. An electric fuse comprising a hollow7 body having an overhanging portion and a plurality of channels 'formed through said overhanging portion, a metallic sleeve sur rounding the hollow body, fuse wires extending through the channels and connected to said sleeve, a cap disk rotatably seated in the top of the hollow body, a contact member carried by the cap disk, means for resiliently holding the cap disk in its seat, and radially extending ribs on the body alternating with the channels, the cap disk having grooves corresponding to the ribs and adapted to receive them, the ribs con stituting guard members between successive 'use wires and holding the cap disk against rotation when engaged in the grooves.

3. An electric fuse plug comprising an insulating body having a circumscribing Hange at one end and having its other end reduced in diameter, the body having also a circumscribing groove directly ad]acent the ilange and having also a cavity in one end that is countersunken, and having channels 'ormed radially ot the bottom of the countersink and passages leading from the outer ends of the channels to the said circumscribing groove, a threaded sleeve disposed upon the body and extending part way over the circumscribing groove, a `fuse disposed in each channel and passage and electrically connected with the sleeve, a disk rotatably mounted in the countersink and having a contact disposed to engage the fuses successively when the disk is rotated, a contact member carried by the reduced end of the body and a resilient (,:oi'iductor between the said contacts disposed to hold the disk yieldably with the first-named coin tact to engage the fuses in the diiierent positions of the disk. v

In testimony whereof, I afiix my signature, in the presence ot two witnesses.

PETER M. CARM] CHAEL. lVitnesses E'UonNn L. CoMMoNDA rnc, ROBERT SKAMEL. 

